Panda 4.0 must be a major update to the actual algorithm versus just a data refresh. Meaning, Google has made changes to how Panda identifies sites and has released a new version of the algorithm today.

Is this the softer and gentler Panda algorithm? From talking to Google, it sounds like this update will be gentler for some sites, and lay the groundwork for future changes in that direction.

Google told us that Panda 4.0 affects different languages to different degrees. In English for example, the impact is ~7.5% of queries that are affected to a degree that a regular user might notice.

Here are the previous confirmed Panda updates, note, that we named them by each refresh and update, but 4.0 is how Google named this specific update: